20845009 has 8 divisors (see below), whose sum is σ = 22300488. Its totient is φ = 19415040.

The previous prime is 20845007. The next prime is 20845021. The reversal of 20845009 is 90054802.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 342225 + 20502784 = 585^2 + 4528^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20845009 - 2¹ = 20845007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20845007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4672 + ... + 7969.

It is an arithmetic number, because the mean of its divisors is an integer number (2787561).

Almost surely, 2^20845009 is an apocalyptic number.

It is an amenable number.

20845009 is a deficient number, since it is larger than the sum of its proper divisors (1455479).

20845009 is a wasteful number, since it uses less digits than its factorization.

20845009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12755.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 20845009 is about 4565.6334719292. The cubic root of 20845009 is about 275.2119974108.

The spelling of 20845009 in words is "twenty million, eight hundred forty-five thousand, nine".